Chaobo Hu1, Weiping Li1, Feng Tian2, Kai Jiang3, Xiaoting Liu3, Jin Cen1, Qiang He1, Zhixin Qiu1, Yvonne Kienast4, Zhong Wang5, Haibin Zhang6, Yuan Ji7, Junhao Hu8, Lijian Hui9. 1. State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China. 2. Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032, China. 3. Interdisciplinary Research Centre on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China. 4. Discovery Oncology, Roche Pharmaceutical Research and Early Development (pRED), Roche Diagnostics GmbH, Penzberg 82377, Germany. 5. Department of Cardiac Surgery, Cardiovascular Research Center, University of Michigan, MI 48109, USA. 6. Fifth Department of Hepatic Surgery, Eastern Hepatobilliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China. 7. Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032, China. Electronic address: ji.yuan@zs-hospital.sh.cn. 8. Interdisciplinary Research Centre on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China. Electronic address: jhhu@sioc.ac.cn. 9. State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China. Electronic address: ljhui@sibcb.ac.cn.
Abstract
BACKGROUND & AIMS: AT-rich interaction domain 1a (Arid1a), a component of the chromatin remodeling complex, has emerged as a tumor suppressor gene. It is frequently mutated in hepatocellular carcinoma (HCC). However, it remains unknown how Arid1a suppresses HCC development and whether Arid1a deficiency could be exploited for therapy, we aimed to explore these questions. METHODS: The expression of Arid1a in human and mouse HCCs was determined by immunohistochemical (IHC) staining. Gene expression was determined by quantitative PCR, ELISA or western blotting. Arid1a knockdown HCC cell lines were established by lentiviral-based shRNA. Tumor angiogenesis was quantified based on vessel density. The regulation of angiopoietin (Ang2) expression by Arid1a was identified by chromatin immunoprecipitation (ChIP) assay. The tumor promoting function of Arid1a loss was studied with a xenograft model in nude mice and diethylnitrosamine (DEN)-induced HCC in Arid1a conditional knockout mice. The therapeutic values of Ang2 antibody and sorafenib treatment were evaluated both in vitro and in vivo. RESULTS: We demonstrate that Arid1a deficiency, occurring in advanced human HCCs, is associated with increased vessel density. Mechanistically, loss of Arid1a causes aberrant histone H3K27ac deposition at the angiopoietin-2 (Ang2) enhancer and promoter, which eventually leads to ectopic expression of Ang2 and promotes HCC development. Ang2 blockade in Arid1a-deficient HCCs significantly reduces vessel density and tumor progression. Importantly, sorafenib treatment, which suppresses H3K27 acetylation and Ang2 expression, profoundly halts the progression of Arid1a-deficient HCCs. CONCLUSIONS: Arid1a-deficiency activates Ang2-dependent angiogenesis and promotes HCC progression. Loss of Arid1a in HCCs confers sensitivity to Ang2 blockade and sorafenib treatment. LAY SUMMARY: AT-rich interaction domain 1a (Arid1a), is a tumor suppressor gene. Arid1a-deficiency promotes Ang2-dependent angiogenesis leading to hepatocellular carcinoma progression. Arid1a-deficiency also sensitizes tumors to Ang2 blockade by sorafenib treatment.
BACKGROUND & AIMS: AT-rich interaction domain 1a (Arid1a), a component of the chromatin remodeling complex, has emerged as a tumor suppressor gene. It is frequently mutated in hepatocellular carcinoma (HCC). However, it remains unknown how Arid1a suppresses HCC development and whether Arid1a deficiency could be exploited for therapy, we aimed to explore these questions. METHODS: The expression of Arid1a in human and mouseHCCs was determined by immunohistochemical (IHC) staining. Gene expression was determined by quantitative PCR, ELISA or western blotting. Arid1a knockdown HCC cell lines were established by lentiviral-based shRNA. Tumor angiogenesis was quantified based on vessel density. The regulation of angiopoietin (Ang2) expression by Arid1a was identified by chromatin immunoprecipitation (ChIP) assay. The tumor promoting function of Arid1a loss was studied with a xenograft model in nude mice and diethylnitrosamine (DEN)-induced HCC in Arid1a conditional knockout mice. The therapeutic values of Ang2 antibody and sorafenib treatment were evaluated both in vitro and in vivo. RESULTS: We demonstrate that Arid1a deficiency, occurring in advanced humanHCCs, is associated with increased vessel density. Mechanistically, loss of Arid1a causes aberrant histone H3K27ac deposition at the angiopoietin-2 (Ang2) enhancer and promoter, which eventually leads to ectopic expression of Ang2 and promotes HCC development. Ang2 blockade in Arid1a-deficient HCCs significantly reduces vessel density and tumor progression. Importantly, sorafenib treatment, which suppresses H3K27 acetylation and Ang2 expression, profoundly halts the progression of Arid1a-deficient HCCs. CONCLUSIONS:Arid1a-deficiency activates Ang2-dependent angiogenesis and promotes HCC progression. Loss of Arid1a in HCCs confers sensitivity to Ang2 blockade and sorafenib treatment. LAY SUMMARY: AT-rich interaction domain 1a (Arid1a), is a tumor suppressor gene. Arid1a-deficiency promotes Ang2-dependent angiogenesis leading to hepatocellular carcinoma progression. Arid1a-deficiency also sensitizes tumors to Ang2 blockade by sorafenib treatment.
Authors: Sun Young Yim; Sang Hee Kang; Ji-Hyun Shin; Yun Seong Jeong; Bo Hwa Sohn; Soon Ho Um; Ju-Seog Lee Journal: Cells Date: 2020-09-01 Impact factor: 6.600